salinomycin and Triple-Negative-Breast-Neoplasms

Metastasis leads to poor prognosis and reduced disease-free survival in breast cancer patients, particularly in those with triple-negative breast cancer (TNBC) which is resistant to common treatments. Anoikis is a type of apoptosis commenced by the detachment of cells from the native extracellular matrix and prohibits the attachment of detached cells to other body organs. Resistance to anoikis is a critical culprit in the development and progression of tumours. It is therefore important to understand the anoikis-related molecular pathways in order to design effective therapies for TNBC. Several compounds have been shown to possess the potential to regulate anoikis in breast cancer cells such as DSF, AEB071, nanoencapsulated doxorubicin, berberine, salinomycin, PEM POL5551, AL10, 5-azacytidine, synthesized flavonoid derivative GL-V9, Tubeimoside V (TBMS-V) and HPW-RX40. We reviewed the molecular basis of anoikis regulation, its potential role as an important target to inhibit metastasis in TNBC, and potential anoikis modulators that could serve as drug candidates.

Topics: Anoikis; Berberine; Chlorobenzoates; Female; Gene Expression Regulation, Neoplastic; Humans; Pyrans; Pyrroles; Quinazolines; Saponins; Signal Transduction; Styrenes; Triple Negative Breast Neoplasms

In order to identify novel treatment principles specifically affecting cancer stem cells in triple-negative breast cancer, we have developed a high-throughput screening method based on the mammosphere and anoikis resistance assays allowing us to screen compounds using a functional readout. The assay was validated against manual protocols and through the use of positive controls, such as the response to hypoxia and treatment with the known cancer stem cell-targeting compound salinomycin. Manual and robotic procedures were compared and produced similar results in cell handling, cell cultures, and counting techniques, with no statistically significant difference produced from either method. The variance between samples processed manually versus robotically was no greater than 0.012, while Levene's test of significance was 0.2, indicating no significant difference between mammosphere data produced manually or robotically. Through the screening of 989 FDA-approved drugs and a follow-up screen assessing the antineoplastic subgroup, we have identified three therapeutic compounds with the ability to modulate the breast cancer stem cell fraction in the triple-negative breast cancer cell line MDA-MB-231, highlighting their potential usage as stem cell-specific adjuvant treatments.

Topics: Antineoplastic Agents; Apoptosis; Cell Line, Tumor; Female; High-Throughput Screening Assays; Humans; Neoplastic Stem Cells; Pyrans; Robotic Surgical Procedures; Triple Negative Breast Neoplasms

Resveratrol (RSVL) a dietary phytochemical showed to enhance the efficacy of chemotherapeutic drugs. Recently, Salinomycin (SAL) has gained importance as cancer therapeutic value for breast cancer (BC), however, its superfluxious toxicity delimits the utility. Taking the advantage of RSVL, the therapeutic efficacy of RSVL and SAL combination was studied in vitro and in vivo system. Firstly, the synergistic combination dose of RSVL and SAL was calculated and further, the efficacy was examined by wound healing, and Western blots analysis. Further, in vivo study was performed to confirm the effect of colony formation and apoptosis detection by flow cytometry based assays. Further, the molecular mode of action was determined at both transcript and translational level by quantitative Real Time PCR combination in Ehrlich ascitic carcinoma model.The combination of IC20 (R20) of RSVL and IC10 (S10) dose of SAL showed best synergism (CI<1) with ∼5 fold dose advantage of SAL. Gene expression results at mRNA and protein level revealed that the unique combination of RSVL and SAL significantly inhibited epithelial mesenchymal transition (Fibronectin, Vimentin, N-Cadherin, and Slug); chronic inflammation (Cox2, NF-kB, p53), autophagy (Beclin and LC3) and apoptotic (Bax, Bcl-2) markers. Further, i n vivo study showed that low dose of SAL in combination with RSVL increased life span of Ehrlich ascitic mice. Overall, our study revealed that RSVL synergistically potentiated the anticancer potential of SAL against triple negative BC.

Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Autophagy; Cadherins; Cell Line, Tumor; Cell Proliferation; Drug Synergism; Epithelial-Mesenchymal Transition; Female; Humans; Mice; NF-kappa B; Pyrans; Resveratrol; Stilbenes; Triple Negative Breast Neoplasms

The aim of this study is to investigate the efficacy of combining a histone deacetylase inhibitor (LBH589) and a breast cancer stem cells (BCSC)-targeting agent (salinomycin) as a novel combination therapy for triple-negative breast cancer (TNBC). We performed in vitro studies using the TNBC cell lines to examine the combined effect. We used the mammosphere and ALDEFLUOR assays to estimate BCSC self-renewal capacity and distribution of BCSCs, respectively. Synergistic analysis was performed using CalcuSyn software. For in vivo studies, aldehyde dehydrogenase 1 ALDH1-positive cells were injected into non-obese diabetic/severe combined immunodeficiency gamma (NSG) mice. After tumor formation, mice were treated with LBH589, salinomycin, or in combination. In a second mouse model, HCC1937 cells were first treated with each treatment and then injected into NSG mice. For mechanistic analysis, immunohistochemistry and Western blot analysis were performed using cell and tumor samples. HCC1937 cells displayed BCSC properties including self-renewal capacity, an ALDH1-positive cell population, and the ability to form tumors. Treatment of HCC1937 cells with LBH589 and salinomycin had a potent synergistic effect inhibiting TNBC cell proliferation, ALDH1-positive cells, and mammosphere growth. In xenograft mouse models treated with LBH589 and salinomycin, the drug combination effectively and synergistically inhibited tumor growth of ALDH1-positive cells. The drug combination exerted its effects by inducing apoptosis, arresting the cell cycle, and regulating epithelial-mesenchymal transition (EMT). Combination of LBH589 and salinomycin has a synergistic inhibitory effect on TNBC BCSCs by inducing apoptosis, arresting the cell cycle, and regulating EMT; with no apparent associated severe toxicity. This drug combination could therefore offer a new targeted therapeutic strategy for TNBC and warrants further clinical study in patients with TNBC.

Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Cycle Checkpoints; Cell Line, Tumor; Cell Proliferation; Cell Self Renewal; Cell Transformation, Neoplastic; Disease Models, Animal; Drug Synergism; Epithelial-Mesenchymal Transition; Female; Histone Deacetylase Inhibitors; Humans; Hydroxamic Acids; Indoles; Mice; Neoplastic Stem Cells; Panobinostat; Pyrans; Triple Negative Breast Neoplasms; Tumor Burden; Tumor Cells, Cultured; Xenograft Model Antitumor Assays